Leak we can’t locate the cause of

[Stephallen]

Hello,
We just had our gunite 10k gal SWG pool put in and filled mid July. Since then we’ve had water on the ground between the house and the pool around the concrete pads we had the PB put down.
The PB has seemingly done everything in their power to find the leak, but so far they haven’t found anything. I’m at a loss as to where else we could look and what next steps might be. If you have any ideas/theories I’d love to hear them so we can guide the PB a little.
1st attempt to find the leak was bucket test and of course we just have a normal amount of evaporation
2nd attempt was just turning off the overflow to see if it was a leak in that water line, that made no impact either.
3rd attempt the PB had a leak detection company come out, they found no leaks.
4th attempt we had a plumber look at the sewer lines and check to make sure we didn’t have any breaks in the sewer line. We also made sure we don’t have a water line leak (the meter doesn’t move in 8 hours).
5th attempt the PB dug up around the concrete pads to try to find it and determined the lights might be the culprit so we had the lights sealed up (I’m sure that’s the wrong terminology).
After this last step the ground has not gotten dryer, but also hasn’t gotten wetter.
They are sending the leak detection company back out next week, but is there a step I’m missing or some area I should have the leak detection company focus on?

 

[ajw22]

You are not losing water from the pool based on the bucket test and you are not losing water from the house based on the meter not moving.

What problem is the damp ground causing?

Do you have an irrigation system?

How close are neighbors who can be losing water?

Are there underground streams in your area?

The pool construction could have shifted the natural underground water flow.

 

[MAPR-Austin]

I've had municipal customers collect water and have it tested. A little chlorine = leak from a water line. A lot of chlorine = leak from pool. No chlorine = ground water.

 

[ajw22]

I've had municipal customers collect water and have it tested. A little chlorine = leak from a water line. A lot of chlorine = leak from pool. No chlorine = ground water.

Test for CYA.

Any CYA is indication it is pool water.

CYA is in no natural water.

 

[markayash]

I've had municipal customers collect water and have it tested. A little chlorine = leak from a water line. A lot of chlorine = leak from pool. No chlorine = ground water.

Might be surprised, I won a bet showing our county water had more chlorine then my pool

 

[Stephallen]

You are not losing water from the pool based on the bucket test and you are not losing water from the house based on the meter not moving.

What problem is the damp ground causing?

Do you have an irrigation system?

How close are neighbors who can be losing water?

Are there underground streams in your area?

The pool construction could have shifted the natural underground water flow.

The house has a water line on it from being wet for so long. I assume after an extended period of time having wet ground under my house would cause foundation problems? Idk, that’s just a theory?
Eventually we want to add turf between the concrete pads and I also worry so much damp ground would cause mold/mildew/smells with the turf. Again, just a theory there too.

No irrigation system. Sorry I should have mentioned that one in the OP.

We don’t have any immediate neighbors, the two lots on both sides of us are empty.

We do back up to a creek and I have considered this to be a possibility. I’m still not sure what I could do if this was the case. I guess we could try to have some French drains installed somehow.

Thanks for the input!

 

[Stephallen]

Might be surprised, I won a bet showing our county water had more chlorine then my pool

Test for CYA.

Any CYA is indication it is pool water.

CYA is in no natural water.

I love this idea, but I can’t get a good sample of water. It’s pretty much just damp and muddy and not standing water. I was hoping when they dug down they would find a pool of water somewhere and we could sample that, but all they found was mud. I assume I can’t sample mud?
Thanks for the input!

 

[reggiehammond]

Can you provide some more photos? Would have to have context of pool equipment pad, pool location, potential route of plumbing.

 

[kimkats]

In to watch and learn.

 

[ajw22]

The house has a water line on it from being wet for so long. I assume after an extended period of time having wet ground under my house would cause foundation problems? Idk, that’s just a theory?

Your house on a concrete slab foundation?

Damp soil around should not cause any problems with the concrete slab.

Eventually we want to add turf between the concrete pads and I also worry so much damp ground would cause mold/mildew/smells with the turf. Again, just a theory there too.

If anything the turf roots will wick up the water and the dampness will keep the grass healthy.

 

[BDY]

I can’t easily see in the pictures - is the wet only on the horizontal ground or also on the vertical house?

 

[Stephallen]

Can you provide some more photos? Would have to have context of pool equipment pad, pool location, potential route of plumbing.

Thank you for the request. Pictures attached. If I need a better picture of the equipment please let me know. I’ve turned it all off and on a few times to see if I could spot any small leaks at start up or stopping and I’m just not seeing anything.

 

[Stephallen]

I can’t easily see in the pictures - is the wet only on the horizontal ground or also on the vertical house?

Both are wet. It started on the ground and has moved up to the foundation. I assume the wet ground has caused the concrete slab to get wet. I’ve attached some better pictures in another reply.

 

[Stephallen]

Thank you for the request. Pictures attached. If I need a better picture of the equipment please let me know. I’ve turned it all off and on a few times to see if I could spot any small leaks at start up or stopping and I’m just not seeing anything.

This is probably the best pic I have of the plumbing that runs under these concrete pads.
Side note..I had no idea how important it would be to get a picture of every single inch of the pool during the build. I’ll definitely be doing that next time around

 

[SoDel]

I love this idea, but I can’t get a good sample of water. It’s pretty much just damp and muddy and not standing water. I was hoping when they dug down they would find a pool of water somewhere and we could sample that, but all they found was mud. I assume I can’t sample mud?
Thanks for the input!

An idea that comes to mind is gather a good quantity of the most wet mud you can find and place it in coffee filters. Keep doing this until you collect enough of the pressings / drippings to test. I’d bet some of the chemists here can suggest much better ways, but just an idea that comes to mind.

Just off the cuff but the bucket test says it’s not pool water but maybe it’s such a tiny leak that the bucket test isn’t giving enough indication. There could be a lot of wheel spinning until you know what type of water it is and where to focus further looking for it. Water and what’s happening underground can be very tricky. I had a pool leak this Spring, and the places where the ground was wet versus where the leak was actually found bore zero correlation to each other. It could be the pool, water main before the meter, underground spring, who knows what else.

In your shoes I’d up the chlorine in the pool well above whatever level is in your tap water if it’s not already there (but within safe levels of course), wait a few days for it to get into the mud if it is coming from the pool, then squeeze enough water from the mud and test for chlorine level and see if that gives at least some indication one way or the other (my guess is the mud squeezings will be too cloudy to test for CYA but worth a try).

 

[kimkats]

Has a line pressure test been done? Especially those that run under the pads. Thinking they could have nicked one with a form stake or such.

 

[Stephallen]

Your house on a concrete slab foundation?

Damp soil around should not cause any problems with the concrete slab.

Yes it’s a concrete slab.

If anything the turf roots will wick up the water and the dampness will keep the grass healthy.

Sorry, I meant synthetic turf.

 

[Stephallen]

Has a line pressure test been done? Especially those that run under the pads. Thinking they could have nicked one with a form stake or such.

Yes, they pressure tested the lines, but they plan to do it again. I’m hoping I can be home when they come so I can pick their brain and just ask them a ton of questions so I can really understand how this all works. I saw one post where they did a sonar test so I’m wondering if I can convince my PB to do that test

 

[Stephallen]

An idea that comes to mind is gather a good quantity of the most wet mud you can find and place it in coffee filters. Keep doing this until you collect enough of the pressings / drippings to test. I’d bet some of the chemists here can suggest much better ways, but just an idea that comes to mind.

Just off the cuff but the bucket test says it’s not pool water but maybe it’s such a tiny leak that the bucket test isn’t giving enough indication. There could be a lot of wheel spinning until you know what type of water it is and where to focus further looking for it. Water and what’s happening underground can be very tricky. I had a pool leak this Spring, and the places where the ground was wet versus where the leak was actually found bore zero correlation to each other. It could be the pool, water main before the meter, underground spring, who knows what else.

In your shoes I’d up the chlorine in the pool well above whatever level is in your tap water if it’s not already there (but within safe levels of course), wait a few days for it to get into the mud if it is coming from the pool, then squeeze enough water from the mud and test for chlorine level and see if that gives at least some indication one way or the other (my guess is the mud squeezings will be too cloudy to test for CYA but worth a try).

I’m willing to do anything at this point. We have the leak detection crew coming back out next week so I can make this the next step if they don’t find it. It may take me while to get clear water from the mud but I think it’s totally possible. I agree there’s really no way of knowing how to solve the problem unless I know the source of the water. I’m still doubtful it’s ground water because we were in a drought for something like 40 days and it was 110 degrees everyday in texas. I would think the ground water would have been deeper down and we likely would have seen ground water at some stage of the build? The first time we saw even the slightest dampness was when they filled the pool.
Although…now that I type all that out I’m beginning to question if the pressure of the water in the pool could actually have diverted the ground water back up toward my house? Perhaps when we were in the building stage the ground water was still able to divert down and around the shell of the pool but once the pool was filled the ground water wasn’t able to divert around and the filled pool is acting like a dam? I’ll figure it out eventually.

 

[reggiehammond]

Have you had the autofill off for a good amount of time?

I think you have a leak - there's too much potential for the auto fill to be leaking and water migrating, or the pool plumbing that's directly underneath. Concrete crew could have hit something after it was buried, or some PVC is not fully glued. Might be a scenario where it only leaks when system is off, etc.